Struct Roles 

pub struct Roles {

    pub validate: Core,
    pub fold: Core,
    pub init: Core,
    pub view: Core,
    pub state_ty: Ty,
    pub event_ty: Ty,
    pub command_ty: Ty,
    pub proposals_name: Arc<str>,
    pub events_name: Arc<str>,
    pub state_name: Arc<str>,
    pub page_name: Arc<str>,
    pub inlined: Vec<Arc<str>>,
    pub shared: Vec<Arc<str>>,
    pub states: Vec<StateRole>,
    pub view_is_per_session: bool,
    pub view_reads_presence: bool,
}

The five things the runtime needs, each a Core value it can call.

This is deliberately still five: a runtime that drives one log, one accumulator and one page is what Phase 1 built and what Phase 3 has not replaced. What changed is that these are now derived from the graph — fusing several folds, inlining or sharing intermediate signals — so the shape of the program and the shape of the runtime are no longer required to be the same.

Fields

validate: Core

(state, proposal) -> Result[list[Event], Rejection] — the authority chokepoint.

fold: Core

(state, Envelope[Event]) -> state — the replay-pure fold.

init: Core

The fold’s initial accumulator.

view: Core

(state, session, presence) -> Html — the client-placed view, with intermediate signals inlined or shared.

Three parameters whether or not the program reads the third: a role the runtime calls has one arity, and a view that ignores its presence argument is cheaper than two code paths that could disagree about which one it has.

state_ty: Ty

event_ty: Ty

command_ty: Ty

proposals_name: Arc<str>

Names, for beck explain and for the report.

events_name: Arc<str>

state_name: Arc<str>

page_name: Arc<str>

inlined: Vec<Arc<str>>

Signals that were inlined into the view rather than surviving as their own node.

shared: Vec<Arc<str>>

Signals read by more than one consumer, and therefore bound once in the sliced view rather than recomputed per use. §5.3’s shared prefix, at compile time.

states: Vec<StateRole>

The durable folds, in declaration order. One entry for the ordinary program; several when the accumulator is fused.

view_is_per_session: bool

view_reads_presence: bool

Whether the page reads presence(), and therefore has an input the log does not contain.

Implementations

impl Roles

pub fn is_fused(&self) -> bool

Whether the accumulator is a synthetic record over several folds.

Trait Implementations

impl Clone for Roles

fn clone(&self) -> Roles

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Roles

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.